Initial observations of water quality indicators in the unconfined shallow aquifer in Dili City, Timor-Leste: suggestions for its management

Abstract

The management of groundwater quality is a critical issue in developing nations where sanitation and drinking water targets are commonly addressed by facilitating access to groundwater, which is then managed as a common-pool resource. We investigate the quality of the shallow unconfined groundwater in Dili's alluvial fan system, which 50% of Dili's rapidly growing population use for all their water requirements. Using the basic chemical and microbiological analyses that are locally available (sulfate, total hardness, fluoride, manganese, iron, ammonia, nitrite, nitrate, total coliform and E. coli) we show that the shallow wells commonly contain enhanced concentrations of dissolved solids and microbiological contaminants (total coliform and E. coli), relative to deeper wells. Cool, shallow wells are worse than warm equivalents. Elevated nitrate and nitrite pollution in the embassy district are tentatively attributed to affluence factors, such as lawn cultivation and water filtration equipment. Microbiological contamination, and associated manganese contamination of groundwater, mimic population patterns, but are concentrated in the finer grained sediments of the small fans and low-slope interdistributary areas. We suggest that rapid development and successful implementation of appropriate sanitation policy in Dili (and elsewhere) is required to address the problematic features of the shallow groundwater system. Success will be predicated on (1) the establishment of baseline data, and (2) development of a systems-thinking approach to holistic water resource management.

Groundwater as a Source of Drinking Water in Southeast Asia and the Pacific: A Multi-Country Review of Current Reliance and Resource Concerns

“…Population growth and urbanization have led to dry season shortages in Dili aquifer [55]. Shallow aquifers in urban areas, which are the primary source of water for households, often receive untreated wastewater [56] and have been found to commonly contain elevated concentrations of dissolved solids and microbiological contaminants [57].…”

Assessing Future Flooding Risk in a Coastal Lagoon Using Hydrogeological Approaches and Analysis of the 2021 Flood Event: A Case Study of Tasi-Tolu Lagoon, Dili, Timor-Leste

“…The hydrogeologic and geologic conditions of Tasi-Tolu Lagoon Apart from being an isolated lagoon, the research site is also a catchment area with its own hydrographic system and is separated altogether from the Dili plain by a spur of schist and metamorphosed basalt bedrock [22]. In terms of hydrogeology, the Tasi-Tolu Lagoon area is composed of localized aquifers with metamorphic rock materials controlled by fracture system in high topographic areas and intergranular aquifers with unconsolidated alluvial deposit materials in low-lying areas [23] [24].…”

Evaluación integral de la gestión del agua subterránea en escuelas rurales en Tandil, Argentina

“…Cabe destacar que las herramientas aplicadas en el presente trabajo han sido útiles para el diagnóstico integral de la problemática, lo que demuestra la importancia del manejo, siendo este el principal punto crítico de la gestión aun cuando las condiciones naturales del recurso son prácticamente óptimas para la provisión de agua potable. Tal situación es común en los países en desarrollo, donde los objetivos de saneamiento y agua potable se abordan, por lo general, al facilitar el acceso al agua subterránea, pero que luego se gestiona sin un enfoque de pensamiento sistémico (Ximenes et al, 2018).…”

“…No obstante, a partir de los resultados microbiológicos se pudo observar que no se logra garantizar la potabilidad en el 73 % de los casos. La detección de problemas microbiológicos es atribuible a las decisiones de manejo; distintos antecedentes han demostrado, a otras escalas de trabajo, que el manejo antrópico juega un rol fundamental al momento de definir la calidad microbiológica del agua para consumo(Ximenes et al, 2018;Faviel Cortez et al, 2019;Martínez-García et al, 2019).En cuanto al análisis del manejo del recurso, la construcción y aplicación del índice resultó de utilidad en un contexto en el cual es necesario dar respuesta a una variable multidimensional, la gestión del agua en las escuelas rurales. La cual no puede ser relevada directamente y además, está conformada por variables que, a su vez,están integradas por otras variables.…”